After you've bred them and received your egg from the Day Care Man, when it hatches into a baby Duskull it should know Destiny Bond. If it is not Female you will have to breed the parents again to get another egg. When you hatch a Female Duskull put it in the Day Care Center, this time with either Solosis, Duosion or Reuniclus that knows Pain Split and Skill Swap. You can get a Solosis in Reflection Cave at Level 22-23 make sure it is Male. It learns Pain Split at Level 33 and Skill Swap at Level 40 so you will have to level it up before putting it in the Day Care Center. Do not let Solosis evolve into Duosion it will try to evolve at Level 32 cancel the evolution or give it a Everstone to hold because it will take you longer to learn Pain Split and Skill Swap.

When it has learnt Pain Split and Skill Swap put it in the Day Care Centre with the baby Duskull that you hatched before that knows Destiny Bond. When they do eventually breed and the egg they produce hatches it will hatch into another baby Duskull that knows Destiny Bond, Pain Split and Skill Swap. To get Dusclops level Duskull up to Level 37 and it will evolve into a Dusclops that knows Destiny Bond, Pain Split and Skill Swap providing you don't forget any of these moves along the way.

As an alternative you can breed a Duskull/Dusclops/Dusknoir with any of these Pokémon to get each move: